In an automatic transmission or the like of an automobile, instead of a slide bearing (bushing), a drawn cup needle bearing having a similar cross-sectional height has recently been used at a position where a radial load is received. As illustrated in FIG. 10, a drawn cup needle bearing 100 includes: a drawn cup outer ring 101 having, at its inner peripheral surface, a raceway surface 101a and having, at its end portions, a pair of flanges 101b, 101c; a plurality of needles 102 placed inside the drawn cup outer ring 101 so as to be rolled along the raceway surface 101a; and a cage 103 having a plurality of pockets for holding the plurality of needles 102.
Methods for providing the foregoing drawn cup needle bearing include: a method in which a swaged portion serving as the flange 101c of the drawn cup outer ring 101 is subjected to anti-carburization, hardening is carried out by a process such as carburization or carbonitriding, and then the needles 102 and the cage 103 are inserted to swage an end portion; and a method in which the drawn cup outer ring 101 is hardened by a process such as carburization or carbonitriding, and then the needles 102 and the cage 103 are inserted to anneal a swaged portion by induction heating or the like and perform swaging thereon. Such methods further include the adoption of a method in which needles and a cage are built into a drawn cup outer ring and then heat treatments such as carbonitriding, quenching and tempering are carried out to perform processes such as the above-mentioned anti-carburization and induction heating on a swaged portion.
On the other hand, there has been proposed a method in which a cage having, at its circumferential part, a radially inwardly deformable portion is used, the cage is placed inside a drawn cup outer ring while being shrunk circumferentially by radially inwardly deforming the cage, and needles are attached to the placed cage, thereby fabricating a drawn cup needle bearing while avoiding the above-described complicated processes (see Patent Document 1, for example).
Also in a radial needle bearing, as illustrated in FIG. 11, a cage 200 is provided, at its one circumferential position, with an elastic connector 201 formed symmetrically with respect to an axial intermediate portion, and this elastic connector 201 is circumferentially increased in diameter and thus placed beyond a flange (see Patent Document 2, for example).